Bound states in functional renormalization group

Renormalization flow of bound states

A renormalization group flow equation with a scale-dependent transformation of field variables gives a unified description of fundamental and composite degrees of freedom. In the context of the effective average action, we study the renormalization flow of scalar bound states which are formed out of fundamental fermions. We use the gauged Nambu–Jona-Lasinio model at weak gauge coupling as an ex...

Cluster Functional Renormalization Group

Functional renormalization group (FRG) has become a diverse and powerful tool to derive effective low-energy scattering vertices of interacting many-body systems. Starting from a non-interacting expansion point of the action, the flow of the RG parameter Λ allows to trace the evolution of the effective one-particle and two-particle vertices towards low energies by taking into account the vertex...

Bridging steady states with renormalization group analysis.

Transitions between different condensed phases, molecular conformations, chemical compositions, or spatiotemporal patterns play important roles in many branches of natural science and at the same time incur serious challenges in their precise characterization. We design an approach for computing connecting orbits bridging steady states based on the renormalization group analysis. The technique ...

Renormalization Group Renormalization Group

Ising exponents from the functional renormalization group

We study the 3d Ising universality class using the functional renormalization group. With the help of background fields and a derivative expansion up to fourth order we compute the leading index, the subleading symmetric and antisymmetric corrections to scaling, the anomalous dimension, the scaling solution, and the eigenperturbations at criticality. We also study the cross correlations of scal...